Dead Men Leave No Prints
by Webster
Summary: John Winchester and his sons arrive in Las Vegas, investigating a murder apparently committed by a dead man. What does Gil Grissom think about all this?


John Winchester's cell phone rang just as he was leaving a gun store in west Texas. It had cost him a bit more than he wanted to spend, but their ammo stock was dangerously low. He'd paid honest cash, didn't dare use even a fake credit card for buying handgun rounds, as they could be traced. A driver's license with a false name he'd used nowhere else, that was safe enough.

"It's Steve Allen, from Las Vegas. Remember me?"

"Right, the skinwalker, back in '93. Still on the force?"

"I made detective in Homicide." There was a hint of pride in Steve's voice. "That's why I called."

"Got another case for me?" John shut the bags in the trunk, held the phone with his shoulder and fished out pen and paper.

Steve hesitated. "Do ghosts leave fingerprints?"

* * *

John reached Las Vegas the next morning, and his sons packed up and followed later that day. It was a little easier on all of them, driving separately. Outside the car, their fights tended to flame up and fizzle out; inside, he and Sam would smolder for hours.

Besides, Sammy was already as tall as his brother. He had to be uncomfortable, crammed in the backseat with his knees around his ears.

John hated working cases in cities this size. It wasn't New York or Chicago, where he could pretend to be law enforcement from the other side of town, but he couldn't possibly pretext as a fed in a town with its own FBI field office. Everyone with a badge in Vegas probably knew everyone else with a badge. Which meant that, without Steve's help, the Winchesters would have a very hard time accessing the police's part of the investigation.

"It started out pretty simple," Detective Steve Allen explained, opening a folder filled with photocopies. "Last Thursday, Eric Harkness was shot with his own gun, weapon found at the scene, nice clear print on the gun that didn't belong to the victim or anyone else in the house. But when we ran the print, we got a match to a guy named Dominguez, who died three months ago."

"Any chance it's just an old print?"

"Family members said Harkness cleaned the gun every Saturday."

"Ghosts aren't physically there, they don't have fingers, much less prints. So, I can think of two possible explanations. The first is that Dominguez isn't really dead, maybe he's some sort of creature who was falsely declared dead. The second is that it really is a spirit who killed that guy, and the spirit left the print deliberately, maybe to send a message. We're going to need some more information here, need to find out if there's any connection between your victim and the owner of the fingerprints."

They looked up at a knock, and Steve opened the door. "Your sons? Good heavens, Winchester, it has been too long." The younger looked remarkably clean-cut, the older one not so much. Matter of fact, had he run into Dean in his days as a beat cop, he'd have shaken the kid down for weapons on the merest sliver of probable cause.

Dean narrowed his eyes at the police officer, and Steve deliberately relaxed. The kid might be trouble, but he was one of the good guys. Supposedly.

The boys sat down, and John quickly recapped. "Listen, Allen, is there any way we can get a look at the evidence ourselves? I'm not asking you to risk your job, but there are things we can't see from copies, things the police wouldn't know to look for."

Steve shook his head, then stopped, staring at Sam. "There just might be."

* * *

The next day, Sam rode with Detective Allen to the police station, dressed in a fresh set of khakis from the Salvation Army and bearing a crisp new Nevada driver's license. The two headed down to the lab, and Allen shook the hand of a dark-haired man with a square jaw..

"Hey, Nick, thanks so much for letting me add Sam to the internship program. He's my friend's son, and really interested in police procedure. Sam, this is Nick Stokes, he's agreed to show you around. Nick, this is Sam Decker." Allen had decided _not_ to ask where the plethora of names and ID cards came from, since he wanted actual proof that his guests were felons only slightly more than he wanted to see another skinwalker. Instead, he dropped off Sam at the crime lab and then headed for his own desk, trying not to think about the Winchesters any more than he could avoid.

Sam spent the day in the lab, filled with a mix of excitement and frustration. Excitement, because the work was genuinely interesting, and because he was hoping to stick around long enough to add this internship to his college applications when the time came to execute The Plan next year. Frustration, because interns weren't permitted in the morgue or evidence room unsupervised, and he hadn't managed to even look at anything connected to Harkness's murder. Dad was going to be pissed when he got back to the room empty-handed.

In fact, Dad was not pissed. Instead, he and Dean were sitting at the table counting their money. "Gambling in a Vegas casino is nothing like gambling in the back of a bar," Dad was explaining to Dean. "For one thing, the person you've got to beat is the dealer, and he's never drunk."

"But the tourists-"

"The tourists are easy pickings, but that doesn't matter when it's the house you've got to beat. Play poker or blackjack, nothing else, unless it's sports bets and you've got an angle. Stay away from the big-money games; the bouncers watch those like hawks. We'll set up a little hustle tonight at a poker table with a mid-sized pot, tomorrow we hit another casino, playing it a little different. We won't win fast, but we'll win enough. Good news is, around here, the other players aren't going to try to beat your head in over losing a couple hundred. Get anywhere at the police station, Sam?"

The abrupt change of topic threw Sam for a moment, but he answered quickly. "I'm in, but I couldn't get a look at the evidence for this case. I'll try again tomorrow, sir."

"Dean and I spent the day knocking on doors, but we couldn't find any connection between Harkness and Dominguez. They died miles apart, never knew each other as far as anyone could tell. And Dominguez has already been cremated. So…." John paused expectantly.

"We keep digging," his sons finished.

By the third day, Sam had figured out that "intern" actually meant "unpaid slave." After the exciting tour of the lab, the day shift supervisor had assigned him to organize reports from old closed cases and scan them into the computer system. At least the night crew felt like teaching him something, which meant that if he got in bright and early, he might get to help them with an active case before they went home. Unfortunately, the Harkness murder had been assigned to the day shift.

_Pick up a folder, feed the documents through the scanner. They're old and fragile, don't break them._ Of course, most of the files weren't murders or kidnappings, they were minor car accidents, drunk and disorderlies, or petty thefts. He'd been at it for two solid weeks and was about to die of boredom, until, midway through the "July 1972" box, he stopped dead. A girl had been found dead in her bed on her twelfth birthday, an apparent suicide, just like the one he'd seen in the newspaper that very morning. Luckily, he was alone in the filing room, so he quickly photocopied the case file. It wasn't anything to do with Eric Harkness, but that was starting to look like a dead end, and this might keep Dad off his back and let him stay here at the crime lab longer.

Besides, Sam wasn't about to ignore a monster killing little girls.

The scanning project was working in reverse chronological order, so it only took him a few minutes to find six other cases. It put him a bit behind on his so-exciting scanning work, but Sam seriously doubted anyone would notice.

That evening, he spread them out on the table in their hotel room. 1973, 1980, 1986, 1989, 1991, 1995 1998, and the news clipping from that morning. Each file held the story of an twelve-year-old girl found dead on her birthday in July, wrists slit with a kitchen knife. "I can't be sure that's the first one, either, because the earlier files aren't in the computer yet. It'd take days to go through every July police report manually."

"This isn't what I sent you to the cops for," John pointed out.

Sam sighed in frustration. "No, but-"

Dad raised a hand. "You're right. This is more important."

Sam stopped, started by his father's show of support. Dean stepped forward, saying, "So the first step is to figure out when this started, right?"

"Dean, hit the library tomorrow, check July headlines from 1973 backwards. Sam, see if you can dig up anything else, maybe talk to some of the old-timers at the station. I'm going to poke around the scene tonight."

"Dad?"

"What?"

"Be careful poking around. The cops here are _good,_ and they might know you were there."

John just grinned. His moods tended to turn black, the longer he stalled out on a case or went without one. The prospect of solving a new one, of stopping something that had apparently killed at least eight children, energized him again, and having Sam fully on board for a change was icing on the cake.

"I picked up EMF at the scene of this year's crime," John announced the next morning. "Strongest around her bed."

"That's where they died," Sam pointed out. "All of the others, anyway. I can't get access to an open case file."

"Then we're looking at a spirit. If we're going to stop this, we need to find the first death."

Dean was the one who found the first case, in 1965, though he went back another fifteen years just to be sure. Sam matched it to a complete file in the police archive room. Anna Thomas, born July 11, 1953, died July 11, 1965. Sam stared at her picture until footsteps past the door of the archive room startled him. What had really killed her? He quickly finished his copying and stuffed the documents into his backpack for later, resolving to catch up on his scanning work.

When he finally got home and spread out the file for his family, a disturbing pattern emerged. Dean was the first to say it out loud.

"She didn't kill herself, she was murdered. And the cops were pretty sure it was her stepdad."

"But they couldn't prove it," Sam finished, voice flat. "It was officially declared a suicide."

"Good work, boys. Now find out where she's buried."

"It's not fair!" Sam burst out. "She just wants justice, she wants someone to know the truth."

"She's a vengeful spirit!" His father retorted. "She's got to be stopped before more people die."

Dean stepped forward, raising a hand. "Look, Sam, the guy's like 80 years old, if he's even still alive. The important thing is to stop the killing."

Sam sat back, still scowling. "I want to know where he is."

"Then we'll find out. And we'll find Anna's grave. Library's open for another two hours tonight."

Sam picked up his backpack and headed for the door, head down. No doubt Dad would insist on salting and burning the corpse tonight, and heading out first thing in the morning.

* * *

Sam knocked softly at the office door. "Dr. Grissom?"

"Sam? What can I do for you?"

"My family's moving on. I just wanted to thank you for this opportunity, and I was wondering… I'd like it if you could write me a letter, that I did this internship here."

"College applications?"

"Yes, sir."

"I'd be glad to." He turned away for a moment, then back to Sam. "You were curious about the Harkness murder, weren't you?"

Sam nodded.

"Well, we made an arrest, and it wasn't the late Mr. Dominguez."

Dr. Grissom pulled out a copy of the dead man's prints. The gun print fit neatly into Dominguez's right index finger.

"Looks good, but it was a false match. They happen," he went on, as the kid blinked in surprise. "If I compared a clean, perfect set of ten prints to another clean set of ten prints, a mistake is almost impossible. But we don't have ten perfect prints, we have one accidental print, which means there's about a 0.1% chance of making a mistake. When we're comparing one crime scene print to one suspect's prints, that means we get it right nine hundred ninety nine times out of a thousand, which makes fingerprinting second only to DNA evidence in its reliability."

Sam nodded intently.

"When we lifted that print in the Harkness murder, however, we didn't have any suspects. So, we ran it through IAFIS, the national database of prints. Problem is, there are millions of people's prints in there, several thousand in the Las Vegas area alone. Which means the probability of at least one false positive rises from zero to something high enough to worry about."

Sam had learned about FBI databases two years before, and since then had wondered on an almost daily basis what they had on his father. Nice to know even the feds weren't perfect.

"So you're saying the print wasn't really a match at all?"

"That's exactly what I'm saying. We arrested Harkness's former business partner, and his prints…." Grissom tapped a few keys and pulled up a second set of fingerprints. The crime scene print matched the partner's right ring finger perfectly.

"I mean, you didn't really think a dead man shot Mr. Harkness, did you?"

Sam's answering laugh was only half a beat too slow.


End file.
